Review of Stunning and Halal Slaughter
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5 Animal welfare impact of slaughter
There are two main considerations for assessing the impact of the actual act of slaughter on the welfare of an animal:
1. Does the neck cut cause pain? 2. How long does it take for the animal to lose enough blood for insensibility to occur and for
any perception of pain or suffering associated with slaughter to disappear? If the answers to those two questions lead to the conclusion that steps need to be taken to alleviate
pain or suffering associated with slaughter then the next question is what is needed to achieve this. 1. Do the stunning methods discussed in chapter 1 achieve the abolishment of such suffering?
2. How long does it take for them to take effect? 3. Do they last long enough for insensibility from blood loss to supervene the insensibility from
stunning without interruption?
5.1 The neck cut
5.1.1 Pain
In the process of cutting the major blood vessels leading to and from the brain a number of other tissues are also severed by the extensive neck cut. These tissues include skin, muscle, trachea,
oesophagus, carotid arteries, jugular veins, sensory and motor nerves and connective tissue. All of these soft tissues are innervated with receptors that will send a raft of impulses to the brain when
they are cut. There is also the possibility that this massive tissue damage and blood loss will cause psychological shock and fear to the animal Mellor et al, 12009.
Up until recently there was no accepted way of measuring the amount of pain associated with the neck cut. As a result there has been a longstanding difference of opinion between scientists. Some
have maintained that if done properly it does not cause pain or distress while others have argued that this much tissue damage is likely to cause unreasonable levels of pain or distress Mellor DJ. et
al 12009. New research techniques have now been developed that allow the quantitative analysis of certain components of the EEG Electroencephalogram and in that way assess the likely
perception of pain more directly Mellor et al, 12009. In this technique animals are maintained under light anaesthesia and then subjected to the
procedure in question e.g. dehorning, castration, neck cut, etc.. This has the advantage that animals are not able to perceive the pain associated with the procedure while still showing
measurable changes in their EEG’s. The EEG traces are recorded and analysed afterwards. A group of scientists at Massey University in Palmerston North, New Zealand, conducted a series of
experiments in this way Gibson et al, 2-52009 and focused on the following issues:
1. The effect of the neck cut. 2. The comparison of the neck cut without cutting the major blood vessels with the severance of
just the major blood vessels. 3. The effect of a non-penetrating captive bolt stun.
4. The effect of a post-cut stun with a non-penetrating captive bolt stunner. In summary the results of these studies were:
Review of Stunning and Halal Slaughter
